Originally Posted by cxwaterboy

I got these numbers from expert flyer. The numbers refer to seat availability and fare class. I is business light and E is essential premium economy. I think O is non-rev with CX or no thrills ticket on other airlines. Every airline is slightly different.

Normally I and E having availability infers the possibility of miles upgrade. However, it is not a correlation. When will your upgrade waitlist clear is a myth.